ceph/src/jaegertracing/jaeger-client-cpp/src/jaegertracing/samplers/RateLimitingSampler.h

   1 /*
   2  * Copyright (c) 2017 Uber Technologies, Inc.
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at
   7  *
   8  * http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16
  17 #ifndef JAEGERTRACING_SAMPLERS_RATELIMITINGSAMPLER_H
  18 #define JAEGERTRACING_SAMPLERS_RATELIMITINGSAMPLER_H
  19
  20 #include "jaegertracing/Compilers.h"
  21
  22 #include "jaegertracing/Constants.h"
  23 #include "jaegertracing/Tag.h"
  24 #include "jaegertracing/samplers/Sampler.h"
  25 #include "jaegertracing/samplers/SamplingStatus.h"
  26 #include "jaegertracing/utils/RateLimiter.h"
  27 #include <algorithm>
  28 #include <string>
  29 #include <vector>
  30
  31 namespace jaegertracing {
  32 class TraceID;
  33 }  // namespace jaegertracing
  34
  35 namespace jaegertracing {
  36 namespace samplers {
  37
  38 class RateLimitingSampler : public Sampler {
  39   public:
  40     explicit RateLimitingSampler(double maxTracesPerSecond)
  41         : _maxTracesPerSecond(maxTracesPerSecond)
  42         , _rateLimiter(_maxTracesPerSecond, std::max(_maxTracesPerSecond, 1.0))
  43         , _tags({ { kSamplerTypeTagKey, kSamplerTypeRateLimiting },
  44                   { kSamplerParamTagKey, maxTracesPerSecond } })
  45     {
  46     }
  47
  48     SamplingStatus isSampled(const TraceID& id,
  49                              const std::string& operation) override
  50     {
  51         return SamplingStatus(_rateLimiter.checkCredit(1), _tags);
  52     }
  53
  54     void close() override {}
  55
  56     Type type() const override { return Type::kRateLimitingSampler; }
  57
  58   private:
  59     double _maxTracesPerSecond;
  60     utils::RateLimiter<> _rateLimiter;
  61     std::vector<Tag> _tags;
  62 };
  63
  64 }  // namespace samplers
  65 }  // namespace jaegertracing
  66
  67 #endif  // JAEGERTRACING_SAMPLERS_RATELIMITINGSAMPLER_H